Safety attachment for elevators



R. L. STUBBS. SAFETY ATTACHMENT FOR ELEVATORS. APPLICATION FILED Nov. 13, 1919.

1,336,664, Patented Apr. 13, 1920.

2 SHEETS-SHEET l.

[W amwm Omega R. L. STUBBS.

SAFETY ATTACHMENT FOR ELEVATORS.

' APPLICATION FILED NOV-13, 1919.

'ZSHET-SH Patented 1,513+ 20.

g Y auuenifoz ROBERT LEE STUBBS, 0F CHABLQ'ETE, IIQR MANUFACTURING- OOl-"VIPAZH Ci SAFETY ATTACI assess-a.

Application filed November 13, 1219.

a citizen of the United States, residing at Charlotte, in the county of lvlecklenburg and State of North Carolina, have invented.

a new and useful Safety Attachment for Elevators, of which the following is a speciiication.

Thisinvention relates to a safety attachment for elevators, one of its objects being to provide an emergency device which will only come into action in the event that the cage of the elevator is carried upwardly past the safety point where the hoisting cable is likely to break and release the cage.

Another object is to provide a device of this character which is simple and compact in construction, can be installed readily and will operate automatically and eiiiciently when necessary. 7

lVith the foregoing and other objects in view which will appear as the description proceeds, the invention consists of certain novel details of construction and combinations of parts which will be hereinafter more fully described and pointed out in the claims, it being understood that various changes may be made in the construction and arrangement of the parts without departing from the spirit or sacrificing any of the advantages of the invention as set forth in the appended claims.

In the accompanying drawing the preferred form of. the invention has been shown.

In said drawings- Figure 1 is an elevation showing the attachment in position and set ready for use.

Fig. 2 is an enlarged elevation of the safety device and showing it tripped and engaging a rack on a car, or cage.

Fig. 3 is an edge of the attaching plate of the attachment.

Fig. 4: is a face view of a rack.

Referring to the figures by characters of reference, 1 designates portions of the guide rails of an elevator shaft and 2 designates a. cage of any desired construction adapted to be actuated by a hoisting cable 3 extending to the wheels 4 on the superstructure at the top of the shaft and which is indicated generally at 5.

Secured to the sides of the cageat the lower ends thereof are plates 6 each of which has a series of ratchet teeth 7, there Specification of Letters Patent.

1'" QIGNOR T0 PARK E, NORTH CAROLINA.

rpn! CAR-GLII-TA,

EFat-ented Apr. E1 192i).

Serial No. 337,638.

being a shoulder 8 at the upper end of each series of teeth and projecting laterally beyond the cage.

An attaching plate 9 is secured at each side of the path of the cage and opposed walls or rails of the elevator shaft. Each attaching plate has a dog 10 pivotally connected to the lower portion thereof and extending upwardly, there being a nose 11 on the dog near its upper end and a notch 12 above said nose. A catch 13 is pivotally connected to the upper portion of the plate 9 and has a lug 1% which normally projects into the notch 12 so as to hold the dog back out of the path of the cage. The free end 15 of the catch projects into the path of the shoulder S but said catch is located so far up in the shaft of the elevator that the shoulder 8 will not come against the free end of the catch unless the elevator ascends too high at a point where the hoisting cable is likely to break because of overwinding. A spring 16 is interposed between the .dog 10 and a lug 17 on the plate 9 and when the dog is held restrained by the catch 13 this spring is held under compression.

It will be apparent that under ordinary circumstances the dogs at the sides of the path of the cage will remain set. If, however, the hoisting cables should overwind and raise the cage too far and to a point where the cage is likely to strike the superstructure and the cable break, the shoulders 8 would come against the projecting ends 15 of the catches and elevate them, thereby removing the projections 14: from the notches 12 and allowing the springs 16 to swing the noses of the dogs into engagement with the racks 7. Thus the cage will be held supported in the shaft.

What is claimed is 1. The combination with an elevator cage and a tooth thereon, of a spring pressed dog at one side of the path of said tooth, a catch for holding the dog under restraint, and means movable with said tooth for engaging and shifting the catch to release the dog when the cage ascends to a predetermined point.

2. The combination with an elevator cage,

a rack thereon, and a shoulder, of a spring pressed dog at one side of the path of the rack and shoulder, a catch engaging the dog and normally holding it under restraint, and means on the catch projecting into the path of the shoulder for actuation thereby gaging and lifting the catch to release the to release the dog. dog when the cage passesa predetermined 3. The combinatlon with an elevator cage, point. r and a rack thereon, or an attaching plate, In testimony that I claim the foregoing 5 a dog pivoted thereon and at one side of the as my own, I have hereto afiixed my signa- 15 path of the rack, a projection on the dog h ture in the presence of two Witnesses.

a catch pivoted on the plate and normally ROBERT LEE STUBBS. engaging the dog to hold it against move- Witnesses: I nient, a spring pressing against the dog, W. F. HOLMES,

10 and means movable with the rack for en- E. T. HART. 

